Liquid metal walls offer the potential for eliminating several of the most vexing issues for solid (e.g. tungsten) divertor options. A liquid metal system is not subject to neutron damage. The solid substrate structure is subject to neutron damage, but not to plasma-material interactions, therefore the choice and fabrication of the substrate does not require low sputtering - or even refractory - materials. In the case of a fast flowing, or self-cooled, liquid metal wall, the substrate need not exhibit high thermal conductivity, which allows consideration of ferritic steels or silicon carbide composites, both of which are known to have high (fission) neutron tolerance, but poor heat removal characteristics. Therefore, liquid metal walls may well present the only solution for plasma-facing components in compact, high fusion power density systems. This presentation will elaborate on the rationale for developing liquid metal PFCs, and discuss the development path.

In addition, the role envisioned for the Lithium Tokamak eXperiment (LTX) in the development of liquid metal PFCs will be discussed, as well as the most recent results from lithium wall experiments. LTX a low aspect ratio tokamak with R=0.4 m, a=0.26 m, and kappa=1.5. Results with both solid and liquid walls will be presented. LTX is a collaborative effort between PPPL and ORNL, with additional participation by UCLA, LLNL, and Johns Hopkins University. This work is supported by USDoE contracts DE-AC02-09CH11466 and DE-AC05-00OR22725.